


Sammy's Sweet Ass

by proserpine_1982



Category: Supernatural
Genre: Alpha/Beta/Omega Dynamics, Alpha/Omega, Community: spn_j2_xmas, Crossdressing, Crossdressing Kink, Knotting, M/M, Teenage Winchesters, Underage Sex
Language: English
Status: Completed
Published: 2012-12-07
Updated: 2012-12-07
Packaged: 2017-11-20 13:17:40
Rating: Explicit
Warnings: Underage
Chapters: 1
Words: 3,196
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/585765
Author URL: https://archiveofourown.org/users/proserpine_1982/pseuds/proserpine_1982
Summary: <blockquote class="userstuff">
              <p>Written from this prompt by the_miss_lv for spn-j2-xmas : -Alpha/beta/omega - Because of the androgynous nature of omegas they're nt normally locked in gender stereotypes, cross dressing is very common. Teen!Jensen/Sam begins cross dressing unaware of how much it turns on Jared/Dean. Would love some up-skirt fucking.</p>
            </blockquote>





	Sammy's Sweet Ass

**Author's Note:**

  * For [Miss_Lv](https://archiveofourown.org/users/Miss_Lv/gifts).



> This is a gift for the_miss_lv for the spn-j2-xmas exchange. It was my first time participating and it was so much fun. I hope this fic does the prompt justice. There were so many first time things for me in this: cross dressing and knotting and writing A/B/O dynamics. I really hope it's good enough.

Dean's never really thought about it. Why should he? It's the way the world is, always has been, and even though he's an Alpha like their dad, it's not like being an Alpha is better or as if Alphas have more status. It was like that once - just like it was once better to be a man than a woman, and that's all a big ol' bunch of bull if you ask Dean.

There is nothing wrong with Sam.

He is exactly like he's supposed to be. And things are the way they're supposed to be. The only thing that seems to be wrong is Dean.

Dad didn't bat an eye when Sam came out of the bathroom wearing a flowery summer dress sort of thing. Dean did a double take. Not because there was anything weird about Sam wearing women’s clothes. He's an Omega, and even though he hadn't really ventured into it before, most Omegas didn't really buy clothes based on gender as much as what they just found appealing and fitting. The reason Dean did a double take was because the dress looked like something that should hang on an 80-year-old grandma. 

Dean had snorted coffee out of his nose and was still chuckling an hour later despite Sam's hissy fit and slamming retreat to the bathroom, and John's hard-as-a-rock palm against the back of his head.

"Come on Dad," Dean laughed, "he looked like an old woman for God's sake."

"Dean. He's fourteen. It's none of your business what he does to figure things out. You only need to watch his back, not what he's wearing." 

Things sort of escaladed after that. First it was the grandma dress, and then things changed quite gradually into slightly tighter jeans, then very tighter jeans and tops with spaghetti-thin straps, and if that wasn't bad enough - skirts! Short skirts. Not just over-the-knee skirts. More like, just under-the-ass-cheeks sort of skirts.

And this is why it seems that whatever is wrong in this scenario is Dean.

Cos whenever Dean sees Sam - navy blue plisse skirt hanging low on pointy hipbones, swaying alluring as he walks, brushing along smooth, milky white thighs, Dean almost chokes on his own saliva. Sam looks like sin personified. So fucking sexy, and he doesn't even know it. He doesn't know what it does to Dean whenever the skirt rides up and a flash of white cotton becomes visible for just a second. Doesn't know that Dean gets painfully hard in his jeans, soaks his boxers with precome every time he watches those long coltish legs with knobbly knees move against the worn down bed sheets whenever Sam is laying on the bed reading and listening to music on his walkman.

It makes Dean's cock drool, makes him feel his knot throb like it wants to pop, and something feral is moving under his skin - it wants him to take, to claim, to breed and mate. 

It makes him want to throw Sam up against the wall, rip off those white cotton briefs, and just watch as his knot stretches Sam's asshole on the verge of tearing while the edge of the skirt brushes the smooth top of his tight bubble butt.

And that shit - that just ain't right.

¤

Dean manages to keep himself in check most of the time. Or maybe it’s more of a question that he’s at least aware that he shouldn’t be staring and okay, outright drooling every time Sam bends over. But seriously – he’s only human, and Sam’s ass with all the training their dad puts them through is so firm Dean is practically sure that he could break his hand on it. 

He’s just happy that he’s managed to keep himself in check enough that he hasn’t sent off any pheromones. Talk about awkward. And death – cause dad would kill him if he smelled Dean going all lust-crazy near Sam. Because of Sam. It’s just getting harder and harder thinking about dead kittens, and old people bumping uglies to keep himself from releasing ‘I’m-gonna-come-fuck-the-shit-out-of-you-Sammy’ scents all over the place. 

This particular afternoon is no different. Really – this afternoon is just really a standard afternoon in Dean Winchester’s life. Dad has dropped them off at a dingy looking no-name motel, Sam is in one of his emo moods, and Dean is torn between wanting to eat and jerk-off. Yeah – standard…

Sam’s seated himself on the bed furthest into the motel room, as always Dean’s got the one closest to the door. Dean’s on his own bed, pretending to watch the little TV, where some kind of talk show or whatever is on. He would be lying if he said he was watching anything else but Sam. 

Sam is looking – Jeez. Sam is looking like no little brother should ever look, and if Dean didn’t know dad would kick his ass, he’d tell Sam to put some decent clothes on. If Sam had been a girl? Well, let’s just say, no sister of Dean Winchester was allowed to walk out showing that much skin. That is just bordering on illegal that’s what that is! And talking about illegal – wanting to grab your 14-year-old baby brother by the asscheeks to bury your face between them and eat him out till he screams is probably illegal in all states countries, planets and so on. But holy shit!

Sam’s wearing his newest skirt – a plaid plisse ass-short school uniform skirt that looks more like a wide belt than a skirt, and is probably used frequently in pornos. Dean’s pretty sure he’s seen at least ten dirty schoolgirl pornos and all the girls were wearing that exact skirt! He’s got on a white polo that cuts off right under his belly button which leaves an almost 6 inch bare piece of skin visible, cause that damn skirt is hanging right below pointy hipbones. Six fucking inches of mouth-watering tan and flawless skin. It looks so silky and delicious, no sign of a happy trail yet, but it’ll get there and when it does Dean will probably have an aneurism and fall over dead. 

Dean bites his lip as he for the hundredth time sneak a glance towards Sam. Sam’s finishing some homework, totally unaware that Dean’s chubbing up in his jeans. He shifts his legs so they slide against each other, and the edge of his skirt dances over strong and practically hairless thighs. Dean groans inwardly. His dick keeps twitching and throbbing, and his lizard brain keeps yelling ‘FUCKBREEDCLAIM!’ 

There’s a sound of something hitting the floor and Dean turns his head only to regret it two seconds later. 

Sam dropped his pencil. He’s on his knees, leaning his upper body off the bed, probably trying to locate the missing pencil and what’s staring at Dean is not his little brother’s face, but his ass turned up high in the air. His skirt has settled itself on his lower back, and fucking hell – Sam’s bought panties.

Dean doesn’t even register when his chest starts to rumble, lizard brain taking over completely, Alpha rising to the surface. What he does register is Sam’s head snapping up at the sound, and how he slowly turns his head, looking back at Dean over one bony shoulder. He looks irritated, slanted eyes narrowed, peeking through his long chocolate bangs. He looks so young and defiant – full of teenage indignation. Dean’s more turned on than he’s ever been, and he growls low in his throat, eyes focused on Sam, and slowly he pulls himself from his seated position. He rolls his body, his feet landing steadily on the floor. He wants. He wants to fuck, claim, breed, knot and mate. Wants to pump Sam full of his come again and again and again till there is no chance in hell Sam isn’t pregnant. 

Another growl escapes his throat, and he watches as Sam first looks confused, then his nose twitches and he sniffs the air. Hazel eyes widen, and Sam’s jaw drops open – a choked of whimper escapes him as he scrabbles against the comforter.

Sam’s movements wake Dean up a bit, and he takes an unsteady step back, forcing the Alpha down. If Sam isn’t feeling this then Dean sure as hell ain’t taking. He might be an Alpha which sort of means he really lacks self-control in all departments, but he’s not an asshole, and he will shoot himself before he lets himself be one of those disgusting excuses for an Alpha that always blames the Alpha in them for raping people. 

Dean blinks, trying to shake himself out of it, brain already working overtime to come up with an excuse to act like a fucking caveman, when the smell hits him. It’s thick and sweet like honey, roasted nuts, and something earthy, tangy and musky. It’s like incense, sandalwood, warm and foreign. It permeates the air and makes Dean cock throb and strain against his zipper. 

He looks up, and everything begins to pound and sizzle at the sight that greets him. Sam’s scooted back towards Dean on the bed. His knees are spread wide, his upper body is flat against the mattress, head turned to the left so he can watch Dean. His right hand is working itself over his cotton covered dick, thick and hard straining against the soft fabric. His left hand clenched under his chin. His eyes are heavy lidded, pupils blown and black, mouth open and pink lips glistening. The damn skirt is edged right over his hole. Now Sam’s wearing panties, so technically Dean can’t see Sam’s hole, but it’s excruciating obvious where it is. Sam’s soaked! There’s a huge dark, wet spot and it’s getting bigger by the second. Dean can see Sam’s fingers glisten from where he’s rubbing his dick, and he knows that the kid’s cock is drooling just as much as his hole is dripping. 

He’s surprised at how much his hand is shaking, as he reaches towards Sam, or more correctly, Sam’s panties. One calloused finger tucks itself under the elastic waistband, and Sam makes a muffled sound against his own fist when the fabric slides wet and clingy over his skin. 

Dean takes a deep breath, and he has to shut his eyes and count to ten unless he wants to pop his knot in his pants like some adolescent loser. When he’s done counting and dares to take a peak, his hand goes directly for his belt cause his pants should have been off like yesterday.

Sam’s hole is right there – looking more mouthwatering than any pie ever made. It’s gleaming and shining, wet with its own fluids. It’s clenching and working, and every time it relaxes the tiniest little gape is visible, which is Sam’s body way of showing that it’s more than ready. His butt-cheeks are round and perfect and there is a tan-line visible just under each cheek. Dean can’t wait to bite that pale flesh and have his hands grabbing on to the place that separates the white skin from the golden tan of his thighs. He wants to leave bruises while prying Sam apart for him, get his face in there to swallow down Sam’s slick, and to fuck those pink muscles with his tongue. 

He toes off his boots quickly, pants falling to the ground by the weight of his belt, he strips of his layers and proceeds to make everything he wants to come true. 

Sam doesn’t even flinch, just pushes back into his hands when they grab on to his thighs. He spreads so prettily, and both of his hands scramble to get a hold of each of his own cheeks to pry himself open. 

Dean gasps and thanks whatever deity who’s decided to listen , when he sees that he didn’t even have to fuck Sam to get him open. When Sam spreads himself he’s so ready that his hole clenches around thin air and Dean is torn between getting a flashlight to take a look inside, and just sticking his tongue in there. He settles for the last, cause he’s pretty sure Sam would kick him in the face if he tried to take a peek inside his ass. 

He moans like a whore when Sam’s taste explodes on his taste buds. Sam’s so warm here, he smells like spices and earth and sweat, but with that subtle kind of vanilla and honey sweetness that screams Omega. Dean licks and eats and fucks, and he gets both his thumbs inside to pry Sam even further apart, cause he can’t get enough, he’s addicted and chases Sam’s taste, craves more of the slickness that is running in a steady stream out of Sam.

Sam’s talking. Well, it’s more like he’s moaning out words of encouragement and praise. Broken off sentences reachDean’s ears while he’s trying to get his whole face inside his little brother’s ass. They’re filled with ‘yes. Fuck. Eat me out. More. Come on. Dean. Right there. Oh. Ohohohohoh’s,’ and Dean growls in response, gets a finger inside Sam, two, three, four – not that Sam needs any prep, but fuck it if Dean doesn’t want to feel him shudder and cramp on his hand when he starts working Sam’s prostate. Sam almost howls, and his upper body comes off the mattress in one swift movement that is so ridiculously sexy and graceful that Dean almost falls off the bed. Sam’s sitting on his hand now. Working himself up and down on it, his head is now laying on Dean’s shoulder, and Dean keeps his hand in place inside Sam, while the other grabs his chin and angles his head so Dean can reach his mouth.

The kiss is wet and violent. Sam’s all teeth and bites and sucks on Dean’s tongue like he’s starving for it. He’s got one huge paw on the back of Dean’s head, pulling his hair and scraping his nails on his scalp. It makes Dean shudder and pant, and for a second he wonders who’s really in charge and if Sam’s some kind of Alpha/Omega hybrid. He wouldn’t put it past his brother who’s always been so unique and set in doing everything his own way.

Dean kind of mewls into Sam’s mouth and Sam releases him, and just looks at him for a second. It stuns Dean to see Sam’s eyes. They look huge and black, and alien, and Dean’s pretty sure that this is what that guy with the fucked up moustache meant when he babbled about looking into an abyss and how it looks back and shit. 

But then Sam smiles – happy and lazy, and the Alpha bursts through Dean’s every pore, and he pulls his hand out of Sam’s hole, doesn’t even bother to flip the skirt up so he can see what he’s doing, and drives his cock into Sam in one fluid movement. 

Sam’s eyes roll back in his head, and he cries out in the most desperate way Dean’s ever heard. 

Sam’s wet and hot and alive inside. His hole is clenching and pulsing around Dean’s cock, it’s like it’s sucking him off, working its drenched rim around his girth. He revels in it for a second, before he feels Sam’s hands find their way to the back of his thighs and Sam’s pulling. He’s trying to get Dean to move to fit more of him inside, and Dean doesn’t want to torture Sam or himself for that matter.

He drags out of Sam slowly, wants to feel how Sam’s rim is clinging to his dick, how Sam’s hole is trying to suck him back inside, and he slams in, his skin smacking against Sam’s, and Sam takes a bruising grip on Dean’s thighs and starts fucking himself in earnest.

Dean’s gone. The Alpha is the only thing left. It’s screaming and growling, finally claiming, fucking and owning. Dean sets a brutal pace. The slap of skin against skin, both of their moans and gasps and growls, the wet sound of suction as Dean’s cock slides in and out of Sam’s hole.

He can feel his knot starting to swell, and he gets and finger inside Sam next to his dick, making Sam buck and curse, then two. He never wants to hurt him. He’ll die before hurting Sam. And even if it seems like it, Dean wants to make sure Sam’s loose enough, that he’s stretched enough so he won’t tear when his knot pops. 

“I’m ready. I’m ready. I can take it. Come on. Fucking knot me jerk.” Sam pants in his ear and Dean pulls on his rim with his fingers again. Not taking any chances.

“Fuck. Come on. Come on. Make me take it. Make me pregnant, you bastard.” 

Fucking Sam. 

Dean almost doesn’t get his fingers out before he feels his knot swelling and he grabs onto Sam’s waist, working his hole against his knot in little jerky movements.

Sam makes a ‘hnnnngh’ sounds when it suddenly pops in and then out again, and then he pushes his ass back so hard Dean almost loses his balance. Dean’s knot pops inside again, and he works his hips to get it out again but this time it’s stuck. 

“Fuck!” He chokes when Sam clenches down hard on it, and comes. Sam coming on his knot is the best thing ever to have happen in Dean’s life. Sam’s writhing then tensing and Dean works his knot deeper inside as Sam makes a strangled noise in his throat and there is a burst of warm wetness from his hole that would be running out of him in a steady stream if it wasn’t for Dean’s knot plugging him up. And that’s it for Dean too. He bites down hard on where Sam’s neck and shoulder meet when he feels the first pulse and throb, and he circles his hips while shuddering against Sam’s sweat slick body as he lets out steady bursts of come inside Sam.

Sam whines under his teeth, and he releases him but soothes the bite happily with little kitten licks when Sam bares his throat to him again. 

Sam’s knees are shaking, and he’s panting like he ran a marathon. Dean gently shuffles and pulls until they’re both laying down catching their breaths on the comforter.

“Fucking hell.” Sam’s the first to break the silence, but Dean’s not worried. Sam’s voice is drowsy and happy, and before Dean can answer in any way the little shit clenches down on his knot still lodge firmly inside of Sam.

“Oh Jesus,” is his very clever response as yet another spurt of come leaves his body, and he secretly hopes that some of his soldiers will have a successful mission and knock Sam up.

Sam just purrs and snuggles further into Dean’s embrace. He licks the bruise that his teeth left on Sam’s neck and Sam gives a full body shudder and a little noise. 

And yeah – this shit might not be right, but he figures he’ll deal with that later. He takes a sniff and something warm and pleasant spreads in his chest, and he smiles. They’ll deal when Sam starts to show.


End file.
